Abstract

Ferromagneticshape memoryalloys are promising active elements for actuators. Our work centered on achieving and maintaining an intermediate fixed deformation so that they can be used as precision positioning actuators. For this purpose, a custom actuator was built using a single crystal of NiMnGa. The results show that these alloys can be controlled within less than 5 nm for both precision and accuracy, a result comparable to piezoelectric ceramics. Interestingly, the defect structure plays a fundamental role in achieving such performance. The stochastically distributed defects determine a progressive diminution of the magnetic field strength required to achieve the control.

Received 20 February 2009Accepted 14 July 2009Published online 07 August 2009

Acknowledgments:

The authors would like to thank the Basque Government’s Department of Industry ACTIMAT Project and the Spanish Ministry of Education and Science Project DPI (Grant No. 2008-03749/DPI) for the funding provided. J.F. would like to acknowledge the EC Marie Curie IIF Program under FP6 for support.